How Do Animals Stay Warm? Make a Blubber Glove

Seals, whales and walruses swim in near-freezing water and stay warm. Desert animals live in heat that would exhaust us. A pair of simple models shows how each does it.

The blubber glove

You need: two large zip-top bags, a tub of vegetable shortening, a bowl of ice water, thermometers and tape.

Spread a thick layer of shortening inside one bag.
Push the second bag inside the first, so the shortening is sandwiched between them. Tape the opening around your wrist.
Put one hand in the blubber glove and the other in a plain bag. Plunge both into the ice water for 30 seconds.
Which hand feels colder? Try holding a thermometer inside each glove, if you have two.

What you notice

The hand with fat around it stays much warmer. Fat is a poor conductor of heat, so a thick layer slows heat loss from the animal’s body to the water. Blubber also stores energy.

Huddling: another way to keep warm

Fill two cups with warm water. Put one alone and cluster three together. Which stays warm longer? Animals such as penguins and some bats huddle, which shrinks the surface exposed to the cold.

How do animals stay cool?

Wrap a thermometer in a wet cloth and put it in front of a fan. Compare it with a dry thermometer. The wet one reads lower, because evaporating water takes heat with it. That’s why we sweat, why dogs pant and why many animals wet their skin or rest in mud.

Large ears also help some desert animals lose heat, because blood vessels near the surface release warmth into the air.

Common mix-ups

“Fur makes heat.” It traps air that slows heat loss.
“Animals feel the cold less.” Many have adaptations that reduce heat loss, but they still manage a balance.

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